Gate for swin g x b b ridg es



(No Model.)

I v I 2 Sheets -Sh eet 1 C. L. PRINDLE. GATfiFOR SWING BRIDGES.

' Patented Apr. 12, 1887.

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I {I I I I I l 1 :l l 'l 'l WEE UNITED STATES v PATEN OFFICE.

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GATE FORISWINYG-BIRIDGES.

SPECIFICATION forming part of Letters Patent No. 360,911, dated April12, 1887.

Application filed September 13, 1883. Serial No: 106,372. (No model.)

To all whom it mag concern:

Be itknown that I, CORYDON L. PRINDLE, of Evanston, in the county ofCook and State of Illinois, have invented a new and useful Improvementin Gates for Swing Bridges, of which the following is a specification,reference being had to the accompanying drawings. The object of myinvention is to make a gate or guard for swing or draw bridges thatshall be closed and opened automatically by the opening and closing ofthe bridge, being entirely out of the way when the bridge is closed forthe passage of vehicles and pedestrians, and following the bridge whenbeing opened for the passage of vessels, effectually closing the spaceat the end of the approach.

The nature of my invention relates to an H shaped gate revolving on acentral pivot and the devices used in operating thesame through .theaction of the bridge in opening and closing, as hereinafter more fullyexplained.

In the accompanying drawings, Figure l is a front elevation of the gate,as seen from the river,when thebridge is open, the gate beingrepresented as closed and the dotted lines indicating its position whenopen, together with the devices attached to the abutment or stationaryspan. Fig. 2 is a side elevation of the same, together with the bridgeclosed, and the devices attached thereto. Fig. 3 is a detail enlargedside view of the bridge and abut- .ment, showing all the devices intheir relative positions. Fig. l is a detail front view of the abutment.Figl 5 is a plan view of the bridge and abutment. Fig. 6 is aperspective view of the abutment and showing the bridge partly open.

The gate consists of the two parallel bars A A, connected inthe middleby the crossbar B, of the same length, and is constructed of eitherwood, iron, or steel of suitable 'dimensions to secure sufficientstrength and inflexibility. The parallel barsAAare slightly curved, asshown in Fig. 2, to conform as nearly as necessary to the curvature ofthe end of the bridge and abutment, the degree of ourvature dependingupon the length of the bridge. The gate revolves on the central pivot,(1, attached to the stationary wood or iron frame 0 at the end of theabutment G. Apin, 0, projects inward toward the bridge from each of thecorners of the gate, being of exactly equal distances apart and from thepivot a, with which the bridge connects and revolves the gate.

The lower ends of the parallel bars A A, when the gate is. open, and theends of the lower parallel bar, when the gate is closed, rest upon theshoulders 43 i and inside the oblique projections m m at the top of theholding devices D D, by which the gate is held in position, whether openor closed, when not being revolved by the bridge.

The holding device D is constructed of wrought-iron, being in the mainpart from one to two inches thick and about four inches in width. It isslightly revolved upon the pivot (Z by contact of the releasing deviceL, projecting from the end of the bridge, against the lower end, torelease the gate,when required, and when moved out of its perpendicularpo sition is carried back against the pin e by the weight'F. The .upperend, an, is turned outward, as shown, in order'to escape the pin a bypreserving an equal distance from the pivot a.

In order to render the releasing device L inoperative upon the holdingdevice D when the gate is not to be released, a triangular device, E, isattached to the lower end of the holding device, which is immovable whenthe contact of the releasing device is against the outer perpendicularside, (when the holding device is to be revolved and the gate released,)but which triangle is revolved on the pivot r, as shown in Fig. 4,whenthe contact is against the inner diagonal side of the triangle, thereleasing device then passing under by raising the triangle, and thusbecoming inoperative upon the holding device. The triangle when releasedis carried back by its own :weight against the pin t.

The carrying device J attached to the bridge, connects with the pin 0and revolves the gate. It is constructed of iron or steel one-half orone inch thick and two or three inches wide,

ing forged into a round arm one or two inches in diameter. It isattached to the bridge by the pivot to at the bottom and the bolt a,passing through the slot in the upper projecting end. It extends downand recedes back from a little above and in front of the upper corner ofthe bridge-railing to nearly the bottom of the bridge in aslightly-curved line, as shown, corresponding to the curvature of theabutment, directly across which the gate revolves in a vertical plane.In order to detach the carrying device from the gate, the end 1) passesover thewedge-shaped disconnecting device I, attached to the abutmentand movable on the pivot 1;, thus throwing the upper end back from thepin 0. When released, it is carried back byits weight against the boltit. In passing in the opposite direction,when the gate is not to bereleased, the end p passes undisturbed under by raising thedisconnecting de' vice, which latter device then falls back into placeagain. The carrying device J and releasing device II are adjusted to thebridge at an exactly equal distance of about six inches from the side.

The gate is opened and closed automatically by the closing and openingof the bridge in the following manner: Vhen the bridge begins to swingopen, all the devices on the side in the direction in which it moves areinactive, as on that side the carrying device J is outside of both thepin 0 at the top and the disconnecting device I at the bottom, and thereleasing device L is outside of the holding device D. On the oppositeside the action is as follows: The releasing device L first comes incontact with the perpendicular side of the triangle E at the bottom ofthe holding device D, and, revolving slightly, the holding device on thepivot d propels the lower end forward, and hence the upper back ward, asindicated by the dotted lines D, Fig. 1, far enough to release thecorner of the gate resting thereon. Then the carrying device J, passingundisturbed under the disconnecting device I at the bottom, by raisingit, as indicated by the dotted lines I, Fig. 1, connects at the top withthe pin a and carries the gate forward with it. When this corner of thebridge reaches the opposite side of the abutment, the gate forces thetop of the holding device D at that side outward far enough to allow thegate to pass to the top of it, when the gate is released from thecarrying device by the latter passing over the disconnecting device 1 atthe bottom, thus throwing back the upper end, as shown in Fig. 3. Thereleasing device L here passes under the triangle E by raising it, asshown in Fig. 4, and thus passes without disturbing the holding device.The bridge is then open and the gate closed. As the bridge closes, thereleasing device L again disconnects the holding device D from the gate,and the carrying device J, passing undisturbed under the disconnectingdevice I, connects again with the gateand carries that corner with it tothe opposite side, where it is released in the manner already described,the carrying device again passing over the disconnecting device, thereleasing device passing under the triangle, and the gate suflicientlyrevolving the holding device to pass to its top. The gate is then openand the bridge closed. It will be seen that when the bridge is openingand the gate closing the pin 0 is between the carrying device J and theside of the bridge, Fig. 6, and the gate is drawn after the bridge, andwhen the bridge is closing and the gate opening the pm is outside of thecarrying device, the gate preceding the bridge.

The gate may be made the full width of the bridge, as here represented,or, as in the case of bridges in three sections having a carriageway inthe middle with narrower sections for pedestrians on the sides, separategates may be used for each section, constructed as herein described andoperatingindependentlyof each other, being so adjusted as to notinterfere in revolving.

I claim for this gate the following essential features, some of the mostimportant of which I find in no other invention for the purpose setforth.

First. Simplicity of construction and freedom from liability to get outof repair, no springs or gears being required or used, the holdingdevice and its triangular attachment and the carrying-lever anddisconnecting device all returning to position through their own weight.

Second. The exact balancing of the gate upon its central pivot and theminimum offriction connected with the several devices making the gate soeasily operated as to be almost, if not altogether, imperceptible to thetender in swinging the bridge.

Third. Operating exactly the same whichever way the bridge is opened andclosed, and at all times covering the exact amount of space left open bythe bridge, and no more, and not requiring pedestrians or vehicles tostop at a distance from the end of the approach to prevent interferingwith its action, and absence of liability to accidents in approaching orpassing off the bridge when in motion.

Fourth. It can be attached to any bridge already construeted withoutmaterial or expensive modification of the approaches.

Fifth. \Vhile constituting only a single rail-guard across the approach,it will prevent persons of any height from walking off, and can be madestrong enough to stop the force of a runaway team.

I claim as my invention- 1. A gate with the parallel bars A A andcross-bar B revolving on a central pivot, substantially as and for thepurposes set forth.

2. The holding device D, in combination with the gate A B, substantiallyas and for the purposes set forth.

ICC

5 4. The carrying-lever J, in combination 3. The triangular device E, incombination tion with the carrying-lever J and the gate A with theholding deviceD, the releasing de- B, substantially as and for thepurposes set 10 vice L, and the gate A B, substantially as and forth.fOI' the S65 fOIbh. L. with the gate A 13, substantially as and for theW'itnesses: purposes set forth. E. F. BODEY,

5. The disconnecting device I, in eombina- W. H, TAYLOR.

